Boring head



June 1, 1948. H. E. TAUTZ 2,442,444

' BORING HEAD Filed Sept. 10, 1945 2 Sheets-Sheet l VENTOR. Hf/Pfif/PT 724/72 A 770 RNE Y.

H. E. TAUTZ BORINGHEAD June 1, 1948 2 Sheets-Sheet 2 Filed Sept. 10, 1945 v INVENTOR.

HERBERT E. 721072.

ATTORNEY.

Patented June 1, H348 BORING HEAD Herbert Tautz} Englewooid, Colo.

Applicationseptember 10, 1945, Serial No."i2615,311

-701aims.

1 This invention relates to a boring head for milling machines and boring-mills. T'he principal object of the invention is to provide -an exceedingly rigid, highly :efiicient and easilyoperated boring head by means-cf which bor ing bars, drills, milling cutters, slotting toels,- and other desired tools of any length may be rigidly and accurately held in place withany desired amount of projection of the tool v zfrom th'ehead.

The usual boring head "or chuck of the ofiset type is supported by means of a taper shank driven into the taper socketoftheboring spindle of the boring machine. The head is placed-on this taper shank. Due to' the solid construction of the shank, it is impossible for the boring har or tool to enter the shank. Thereforethe bar or tool must project from the chuck rorsubstantially its entire length. This requires constant changing of boring bars of different lengths, or changing the position of the work on'the table in order to place the-cutting edge atthe proper work position. For close Work positions shorter bars must housed, and for more distant positions the short bars must beremoved and replaced by longer bars or, if possible, the workmust be removed.

In this improved boring head, a long bar :can pass entirely through the head and into the'ehol- W taper spindle of the boring millior .c'lose work positions, or extended outwardlyiand locked in any desired position to accommodate the desired reach without the neoessity-of' changing boring bars or moving the Work-piece.

Much time is expended by-the operator :of a

milling machine or boring millinplacing the Work in the proper position to suit-the length-or projection of the drill or other toolin the, chuck. With this invention, however, the :Work-can be placed close to thechuck, where great-tool ngidity is obtained regardless of the lengthsoflthe drill or other tool, since the tool can he slid into the chuck with only the minimum necessary projection therefrom, and for other. parts of the ing boring bar for a headuotthis typein which a relative1;y gsmall bar smay-be telesooped into a larger bar-so as: to reinforcethe smaller barsior as much of its length as possible,--withthegiven work, to reduce flexur-e and:inaccuratecutting, and to provide telescopic reversible barshavin large d ameter cutters on "one extremity, and sma diar e e ru r wn th :Qt eat em t which can he placed the -;head with -;either extremity foremost.

1 O he o j c s a d a v nta s res e in t .detail construction of 'the invention, which is desi n d o a r ic tyv ec o mandefi qie cy- T ese w b ame m reappa en i em-ther owing "descrip n- In t e ic lew s -det i ed --ide.scr 'pt n he in tio e e n ha qtostheeac qmpan d awin wh m t-part here l ik wnumerals- -refer to like parts in ;all--. ,v-iews qfrthedrawin a d t u hout the s ri t onin h li ing;

l-Fig. '1 a -detail-section=through therexlilfemity of a t pi al b r .ne millspindle 0f h -typ u o which the imp ov head is as ne 'azfor at a hment;

Fig-: 2 -;is a yface view 10f the 1 typical spindle of'l i ..1;

. Fig. a ls -a front eface view 10f the improved shoring head, designed ::for :attachment oto vii-he spindle of Fig. 1;

:Eig.-4- -is a .rear face view of the improved bori-rie-;'-head, With: its; verepl tei pa t llyabreken away to illustrate t-heinterior iconstruotizm;

Ei 'ia top i w th eqi;

:Fia 45 d t il se tie m Vi w t ken-e e li 5 1 ,z

E-ig. 7 is a longitudinal-section throngh the b in adiil u tm na a n--=t-h extr.emit o th ir-m a s ind -42 Wed-@3 1 o drappea in u e-w haen m-= imp e s e es o n mete in pl c wh e n;

ie. 1 1a ,td e s ne 12 a alterna ez o m ao berinezba ww ichmay peru ed... th mp head;

Fig. -10 is an ;.e nlarged detailesec-tionetaken on the uppe o t on 'E iD 'S -J. .i3,; l1ustrat1ns .QfE e I-cQ tr hdia an rea in -la .use ah impmvedh ad; an

flie 1 1 a -:s1et.ai1 wiac avi w :Ea-ebear nse tamin u -n ed'e n ot fi bearin -o iea 1 -W l "t e nipr.w d* ea i .mcreart cn arly d ned.forriattachmenhtolaholl w. taneredaand flanged boring mill spindle, such as illustratedlin attachment screw holes l4 and with key slots [5 r and key screw holes I6 for the attachment of v various tools, face plates, and the like.

The improved boring head employs a drum-like casing ll, preferably provided with knurled bands l8 on its exterior. The back of the casing I1 is hollowed out to form a cavity l9 of a diameter to accurately receive the flange I3 of the spindle ID, the cavity extending over half way through the thickness of the casing.

The improved head is attached to the face of the flange l3 of the spindle III by means of two attachment screws 29 which extend through shouldered counterbored openings 2| in the easing [1 and are threaded into any opposite two of the screw holes l4 in the spindle. When in place, the flange I3 of the spindle fits accurately into the cavity E9 in the casing to absorb all lateral thrust.

Two segment-shaped mortised slide blocks 22 are attached to the bottom of the cavity IS in parallel relation at each sid thereof by means of hollow head cap screws 23. The cap screws 23 are threaded into the casing I! with their heads resting in counterbores in the blocks 22.

The straight sides of the blocks 22 are undercut to accurately overlap stepped edges 24 formed on the sides of a slidable collet base 25, so that the latter may move diametrically of the axis of the casing 11. The base 25 supports a collet sleeve 26 which projects forwardly through an elongated opening 27 in the front of the casing H. The collet sleeve 26 is provided with the usual tapered axial socket 28 for receiving a conventional collet 29. The collet 29 is held in place in the socket 28 by means of a taper collar 30 which is clamped against the collet 29 by means of a collet nut 3| threaded onto the extremity of the collet socket sleeve 26.

The collet base 25 may be moved diametrically by means of a lead screw 32 which is threaded diametrically through a cylindrical, rotatable bronze nut 33 inset in the base 25. The screw 32 is formed with a thrust flange 34 which seats against the inner race of a ball thrust bearing 35, the outer race of which is held in a receiving socket in the casing I! by means of an annular retaining nut 36, shown in detail in Fig. 11. An index nut 38 is threaded onto the extremity of the screw 32 against the opposite side of the inner race of the bearing 35 and is held in place thereon by means of a retaining screw 31 which is threaded into the extremity of the lead screw 32.

It can be readily seen that, as the index nut 38 is rotated in either direction, it will in turn rotate the screw 32, causing the latter to move the collet base 25 diametrically in either desired direction. The index nut 38 is provided with spaced wrench sockets 39 to facilitate its rotation by means of a suitable spanner wrench (not shown). The nut 38 carries a micrometric index scale 40, as shown in Fig. 5, the positions of which are indicated by an indexing marker 4| on the casing to the other side of the axis. This screw is accurately machined so as to contact the base 25 at the point where the axis of the collet '29 coincides with the axis of the spindle ID. This enables the collet to be quickly and easily centered by simply rotating the nut 38 until contact is established with the stop screw 42.

The base 25 may be locked in any desired posi- 4 tion by means of a locking screw 43 which passes through a clamping block 44 riding in a radiallyextending block socket 45 in the face of the casing ll. The screw 43 passes through a slotted guide opening 46 in the bottom of the socket 45 and is threaded into the base 25. It can be seen that, if the screw 43 is tightened, it will act to clamp the block 44 against the bottom of its socket 45, preventing radial movement of the base 25.

The collet 29 can, of course, receive any desired tool, such as a drill, boring bar, milling head, slotter, etc. As illustrated in Fig. 7, it is supporting a telescoping boring bar consisting of a hollow outer bar 4'! terminating at its outer extremity in a conventional collet 48 actuated by a collet nut 49. The collet 48 engages a smaller boring bar 50 which is slidable within the hollow interior of the outer boring bar 41, and which can be clamped at any desired degree of extension therefrom by means of the collet nut 49. The bar 50 terminates in any desired boring tool 5|, clamped in place therein by means of a clamp screw 52.

For work close to the boring head, the bar 41 can be forced fully into the collet 29, since it can extend into the hollow interior of the spindle ID. The boring bar 50 can then be forced into the bar 41 to position the tool 5| at the desired point. For work at a greater distance from the boring head, the bar 41 is withdrawn as far as possible so as to limit the amount of extension of the smaller bar 50 as much as possible to prevent bending or chattering of the smaller bar. This allows deeper cuts to be made than could have been made with the smaller bar extending the full distance.

In Fig. 9 an alternate form of telescoping boring bar is illustrated, comprising a hollow outer bar 53 in which an inner bar 54 is accurately and slidably mounted. The bar 54 can be locked at any desired projection by means of set screws 55, the points of which engage in a key groove 56 in the smaller bar to effectively prevent relative rotation between the two bars.

The smaller bar 54 terminates in a boring tool 51 held in place by set screws 58, and the larger bar terminates in a second boring tool 59 held in place by similar set screws 60. The boring bar is used in the head similarly to the previously described bar, that is, the larger bar 53 may be mounted in the collet 29 with either extremity projecting forwardly. The larger bar serves as a stiffener and reinforcement for the smaller bar 54 on long reaches.

The segment blocks 22 and the base 25, with its retaining screws 23, are covered by means of an annular cover plate Bl held in place by means of countersunk screws 62 threaded into S the heads of the screws 23. The slotted owning 21in the face of the casing I1 is concealed by means of a flanged cover ring 63 threaded onto the col-let socket member 23 and attached to the block.

A drill or slotting tool can be used in the collet and for Work which can be positioned close to the head, the drill or other tool can be slid through the head into the hollow spindle with only the necessary amount of projection so that fiexure of the drill or tool is reduced to a minimum and extreme accuracy may be attained.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, Without departing from the spirit of the invention.

Having thus described the invention, what is claimed and. desired secured by Letters Patent is:

l. A head for boring machines of the type having a hollow boring spindle terminating in a fianged'extremity with threaded attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachment holes of the spindle; an elongated collet base resting in said cavity; a segment-shaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening at the axis of said casing; a collet carried at the forward extremity of said collet sleeve; the hollow of said sleeve extending through said base in alignment with the hollow of the spindle; and means for moving said collet base along said segment blocks.

2. A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity with threaded attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachment holes of the spindle; an elongated collet base resting in said cavity; a segment-shaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening at the axis of said casin a collet carried at the forward extremity of said collet sleeve, the hollow of said sleeve extending through said base in alignment with the hollow of the spindle; a nut imbedded in said collet base; a lead screw extending diametrically into said casing and being threaded into said nut; and a thrust bearing preventing longitudinal movement of said lead screw.

3. A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; means for attaching said casing to said flanged extremity; an elongated collet base resting in said cavity; a segment-shaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardl y from said block through an emanate-a opening at the axis of taid eating; a collet can rie'd at the forward extremity'of said collet sieeve, the honow of said sleeve extending through said base in alignment with the hollow of the spindle; and means for moving said collet base along said segmentblo'cks.

4. 'A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity with threaded "attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extrernity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachrnent holes fof the spind1e;an elongated collet base resting in 'saidcavity; a segment-shaped slide block secured in said cavity at each side of said base, the inner edges of 'said blocks over-- lapping outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening at the axis of said casing; 'a collet carried at the forward extremity of said collet sleeve, the hollow of said sleeve extending through said base in alignment with the hollow of the spindle; means for movme said collet base along said segment blocks; an annular cover plate fitted into said cavity over said collet base and guide blocks, plate having an axial opening exceeding the diameter of the hollow in said collet sleeve; and means for securing said cover plate in place.

5. A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity with threaded attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachment holes of the spindle; an elongated collet base resting in said cavity; a segmentshaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening in the axis of said casing; a collet carried at the forward extremity of said collet sleeve, the hollow of said sleeve extending through said base in alignment with the hollow of the spindle; means for moving said collet base along said segment blocks; and attachment screws fitted into counterbores in said guide blocks and being threaded into said casing for securing the former to the latter.

6. A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity with threaded attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachment holes of the spindle; an elongated collet base resting in said cavity; a segmentshaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening at the axis of said casing; a collet carried at the forward extremity of said collet sleeve, the hollow of said sleeve extending through said base in alignment with the hollow of the spindle; means for moving said collet base along said segment blocks; attachment screws fitted into counterbores in said guide blocks and being threaded into said casing for securing the former to the latter; a cover plate fitted into said cavity over said collet base and said guide block, said cover plate having an axial opening exceeding the diameter of the hollow in said collet sleeve; and plate screws passing through said plate into threaded receiving sockets in said attachment screws.

7. A head for boring machines of the type having a hollow boring spindle terminating in a flanged extremity with threaded attachment holes therein comprising: a cylindrical casing having a cavity in its rear face to receive the flanged extremity of the spindle; attachment screws extending through said casing from the front face thereof for threaded engagement with the attachment holes of the spindle; an elongated collet base resting in said cavity; a segmentshaped slide block secured in said cavity at each side of said base, the inner edges of said blocks overlapping the outer edges of said collet base; a hollow collet sleeve projecting forwardly from said block through an elongated opening at the axis of said casing; a collet carried at the forward extremity of said collet sleeve, the hollow of said sleeve extending through said base in REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 85,329 Reid Dec. 29, 1868 981,062 Casler Jan. 10, 1911 1,125,649 Carr Jan. 19, 1915 1,256,462 Frey et al. Feb. 12, 1918 2,393,777 Hughes et al Jan. 29, 1946 FOREIGN PATENTS Number Country Date 142,194 Great Britain 1920 

